Abstract

We investigated the abundance of adult caddisflies in the precincts of food and pharmaceutical factories. The objective of this study is to clarify the abundance of adult caddisflies from the cooling tower and catch basin by a light trap in the vicinity of food and pharmaceutical factories. In addition, to clarify the role of vegetation near factories for adult caddisflies, an investigation of the number of insects using vegetation was conducted with light traps. The light traps were operated in mid May−early June, end July−mid August, and mid−end October 2009. At St. 1, the highest number of hydroptilid adults was collected in cherry trees (64 individuals), followed by the cooling tower (38 individuals), and the catch basin (only one individual). On the other hand, the highest number of hydroptilid adults at St. 2 was collected in the catch basin (15 individuals), followed by cherry trees (7 individuals), and cooling tower (6 individuals). No hydroptilid adults were collected in the cooling tower and vegetation at St. 3. These results suggest that factories may be exposed to periodic invasions of adults from not only natural aquatic ecosystems, rivers and lakes, but also small man-made aquatic ecosystems, cooling towers and catch basins, in the vicinity of factories.